The relative carcinogenicity of a number of conformationally biased N-nitrosamines appears to be related to the acidity of an hydrogen alpha to the nitrosamine function and in a plane perpendicular to that containing the nitrosamine and its substituents. This proposal is designed to test this apparent correlation by structure/function studies of a number of novel N-nitrosamines. A detailed study of an apparent exception to this correlation, N,N-dibezylnitrosamine is proposed. The N-nitrosamines will be examined for their mutagenic potential in the Ames Assay directly and in the presence of a metabolic activation system. Carcinogenicity of selected compounds will be examined in whole animal studies. The significance of the interaction of N-nitrosamines with polyhydroxy compounds such as ascorbic acid and sucrose is also proposed.